Applicability Of Electrochemical Detection Methods And Quality Control Research Of SBS Modified Asphalt Content

Polymer SBS modified asphalt with outstanding performance under high temperature, low temperature performance, elastic recovery properties and thermal performance, is widely applied in the construction of high-grade highway. However, there is no standard, rapid and accurate detection method in domestic and foreign for SBS content detection, the real-time supervision of SBS modified asphalt cannot be achieved in the real. Therefore, it seriously affected the factual and objective evaluation of quality management staff on the properties of SBS modified asphalt.Zhu zi qiang, zheng-chun Liu and others who are the member of Central south university SBS project, after analyzing and summarizing predecessors' research results, Based on SBS molecular Carbon-carbon double bond bonus oxidation characteristics, through addition REDOX reaction method was proposed to measure Carbon-carbon number of double bonds. Based on this idea, through repeated experiments, a set of new SBS content detection method is proposed by the research group, namely "the SBS dosage electrochemical analysis technique". The core principle of this assay is an addition reaction with the addition of a known amount of reagent and SBS bitumen molecules, then the test reagent consumption obtained by addition of redox titration, and thus indirectly of the amount calculated SBS asphalt. The SBS content electrochemical analysis technique can stable, fast and accurate implementation of SBS content detection, detection accuracy up to ± 0.1%.Various proportioning of modified asphalt were made through different types of SBS, dosage and a variety of admixture, then the applicability of the "SBS content electrochemical analysis technique" were demonstrated by experiments. The test results showed that the detection method can accurately detect the content of various ratios SBS modified asphalt and with good applicability; In addition, we also analyzed the influence of solubilizing agent, stabilizer, nano montmorillonite, and additives on the detection accuracy, whose purpose is to ensure that the detection method can obtain accurate test results in engineering application.Based on the SBS content electrochemical analysis technique, Choose three kinds of modified asphalt be to do storage stability evaluation. The modified asphalt of top and bottom samples were taken after segregation, then softening point of the sample test, SBS content detection and dynamic shear rheological(DSR) test(test rutting factor, calculated asphalt segregation rate) were carried out. The storage stability was comprehensive evaluated by low softening point, the SBS content and segregation rates. The results showed that segregation softening point test can evaluate linear SBS modified asphalt storage stability, but the star-shaped SBS modified asphalt segregation degree evaluation is put in bigger error; The actual content of SBS in the top and bottom of the asphalt after segregation can be directly detected by the SBS content electrochemical analysis technique, it can also evaluate the storage stability of modified asphalt in detail; Dynamic shear rheological experiment only according to the asphalt high temperature performance with rational selection of test temperature, can well evaluate the storage stability of modified asphalt.Through the blind test, the effectiveness and detection accuracy of the SBS dosage electrochemical analysis technique has made full validation; The SBS dosage electrochemical analysis technique has achieved good effect in engineering testing applications, this testing technique has a good engineering applicability.